Die design with integrated assembly aid

ABSTRACT

An upper die portion of a die head for aligning probe pins in first array of first micro-holes formed in lower die portion of the die head, which generally includes a spacer portion and is adapted to contact lower die portion is typically positioned between second surface and support frame and includes a second array of second micro-holes adapted to receive probe pins generally is in contact or close proximity to first assembly aid film and has a third array of third micro-holes adapted to receive probe pins and third array of third micro-holes are patterned to align with one another but are both offset with first array of first micro-holes by approximately the lateral distance between probe tip and probe head.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. application Ser. No.10/987,039, filed Nov. 12, 2004, which claims the benefit of U.S.Provisional Application No. 60/519,966, filed Nov. 14, 2003, each ofwhich is hereby incorporated by reference as if fully disclosed hereinin its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a vertical pin integrated circuit probingdevice, and more particularly to an assembly apparatus and method forloading probe pins into a die head assembly of the vertical pinintegrated circuit probing device.

2. Description of the Related Art

U.S. Pat. Nos. 6,297,657 and 6,633,175 illustrate vertical pin probingdevices and are incorporated by reference as if fully disclosed in theirentireties herein.

One type of vertical pin probing devices utilizes a buckling beam diedesign. As described in U.S. Pat. No. 6,297,657, an integrated circuitor other device under test is supported on a movable chuck. Theintegrated circuit typically has a pattern or matrix of contact pads tobe simultaneously probed by a vertical-pin integrated circuit probingdevice, such as the probe head sold under the brand name COBRA® byWentworth Laboratories of Brookfield, Conn. The probing device includesa lower die with a group of holes and an upper die with a group of holesseparated by a spacer and carrying multiple vertical pin probes. The diematerials are typically made of a plastic insulating material such asthose sold under the brand name Delrin®, an acetal resin that is aregistered trademark E.I. duPont de Nemours & Co of Wilmington, Del., alow expansion metal such as those sold under the brand name Invar®, anickel alloy that is a registered trademark of Imphy, S.A., or a ceramicsuch as silicon nitride.

Each probe pin has a probe tip that protrudes from a hole in the lowerface of the lower die and an exposed head that protrudes from holes inthe upper side of upper die. Holes containing opposing ends of thevertical probe pins are slightly offset from one another and the probepins are curved in a snake-like configuration to promote buckling, so asto create substantially uniform contact pressure on the integratedcircuit pads despite any slight vertical unevenness or misalignment.

With reference to FIG. 1, a partially-assembled portion of a bucklingbeam die 10 as known in the prior art includes of a lower die 12, probepins 14, and an assembly aid film 16. Lower die 12 contains an array ofmicro-holes 18 into which probe tips 20 are inserted. Assembly aid film16 contains a matching pattern of micro-holes 22 punched into the film.One edge 24 of a small piece of assembly aid film 16 is adhered, e.g.,using tape or similar, to top 26 of lower die 12 so that it isapproximately positioned over micro-holes 18. Each probe tip 20 isinserted into one of lower die micro-hole 18, and then probe head 28 isinserted up through a corresponding micro-hole 22 in assembly aid film16 to hold probe pin 14 in position. This process is continued untileach of probe pins 14 are in place. Insertion of probe heads 28 requireslifting assembly aid film 16 to provide sufficient clearance to slipeach probe head under the film and up through the proper one ofmicro-holes 18. As the assembly proceeds, it is necessary to tie downassembly aid film 16 periodically to prevent it from lifting up offprobe heads 28 of the contacts that have already been installed.Regardless, assembly aid film 16 occasionally lifts off probe heads 28resulting in the need for a partial or complete re-assembly. The processof fitting probe heads 28 up through micro-holes 22 in assembly aid film16 also presents opportunities for each of probe pins 14 to beinadvertently bent.

After each of probe pins 14 have been loaded into lower die 12 andassembly aid film 16, it is necessary to cut the film so that it fitsentirely inside an upper die cavity, and to remove the tie-down wires.This process often results in assembly aid film 16 lifting off one ormore of probe heads 28, again requiring a partial or complete re-buildof the assembly. After assembly aid film 16 has been cut and the wiresremoved, it is necessary to install an upper die 30. As shown in FIG. 2,this requires aligning upper die 30, which has an array of micro-holes32 matching the pattern of micro-holes 18 and 22 in lower die 12 andassembly aid film 16, respectively, over array of probe pins 14 suchthat each of probe heads 28 lines up with a respective one of themicro-holes in the upper die. This is a delicate operation, as typicallyeach of thousands of probe pins 14 must pass through one of micro-holes32 simultaneously in order to avoid bending probe pins. Consequently,each of micro-holes 32 in upper die 30 are larger than those in lowerdie 12 and in assembly aid film 16 to facilitate assembly. Also, stillreferring to FIG. 2, upper die 30 is conventionally made by startingwith a round disk of polyimide material of approximately 0.1 inchthickness, and milling out a cavity 34 leaving a thin “web” on the orderof 0.010″ thick through which the pattern defining array of micro-holes32 is drilled. It is often difficult to keep such a thin web of materialflat across the array due to unbalanced internal stresses in thematerial after milling, moisture absorption, etc., and may result in arelatively low yield rate for upper dies.

After upper die 30 is installed, alignment pins (not shown) are insertedto correctly align the upper die with lower die 12 dies, and screws (notshown) are installed to hold the upper and lower dies together. Probeheads 32 are then lapped in order to arrive at a consistent over-allprobe pin length throughout the array. One consequence of the lappingprocess is that lapping debris passes through over-sized micro-holes 32in upper die 30 and collects on assembly aid film 16 inside the headassembly. This debris is conductive and must be removed to avoidelectrical shorting between contacts. It is therefore necessary toremove upper die 30 after lapping in order to adequately remove thedebris. The removal of upper die 30 presents a further opportunity forassembly aid film 16 to lift off probe heads 28, requiring a partial orfull re-build of the assembly. It also requires upper die 30 alignmentand assembly to be repeated, presenting another opportunity for bendingprobe pins 14 if alignment is not perfect.

One of the advantages of buckling beam technology is repair-ability.Since the probe pins are not permanently bonded to the test electronics,it is possible to replace damaged probe pins rather than discard theentire assembly. The repair process with the conventional design asillustrated in FIG. 2 may be problematic. The repair process requiresremoval of upper die 30 to gain access to probe pins 14. A damaged oneof probe pins 14 is then extracted by pulling it through assembly aidfilm 16, and re-inserting a new probe pin through the same assembly aidfilm hole. There are several problems that may arise when using thistechnique. First, the removal of upper die 30 may cause assembly aidfilm 16 to lift off one or more of probe heads. Static electricitysometimes results in assembly aid film 16 adhering to the underside ofupper die 30 and coming completely off the array, resulting in the needfor a complete re-build.

Assuming upper die 30 is successfully removed, any of probe pins 14 thatare damaged must then be withdrawn through assembly aid film 16. Sincemicro-holes 22 in assembly aid film 16 are “tight”, e.g., with adiameter on the order of 0.0001 inch larger than the diameter of typicalprobe pin 14, the assembly aid film must be slightly torn in order forthe probe pin “swage” to pass through the film. This “tugging” onassembly aid film 16 presents another opportunity for the film to liftoff of one or more of probe pins 14.

Assuming a damaged one of probe pins 14 is successfully removed andanother probe pin inserted, the particular one of micro-holes 22 inassembly aid film 16 is now enlarged, causing potential difficulties inaligning the new probe pin with its associate micro-hole 32 in upper die30. Also, enlarged one of micro-holes 22 in assembly aid film 16 allowsprobe pin 14 more freedom of movement, which may allow it to contact aneighboring probe pin in tight tolerance applications resulting in anelectrical short circuit.

SUMMARY OF THE INVENTION

One aspect of the present invention is an upper die portion of a diehead for aligning probe pins in a first array of first micro-holesformed in a lower die portion of the die head, which includes a spacerportion including first and second surfaces, the first surface adaptedto contact the lower die portion, a support frame, a first assembly aidfilm positioned between the second surface and the support frame, andhaving a second array of second micro-holes adapted to receive the probepins.

Another aspect of the present invention is a die head includingalignment mechanisms for aligning probe pins in the die head, whichincludes a lower die portion having multiple surfaces, at least one ofthe multiple surfaces having a first array of first micro-holes adaptedto receive the probe pins, an upper die portion having a spacer portion,a support frame, and a first assembly aid film, the spacer portionincluding first and second surfaces, the first surface in contact withat least one of the multiple surfaces of the lower die portion, thefirst assembly aid film positioned between the second surface and thesupport frame, and the first assembly aid film having a second array ofsecond micro-holes adapted to receive the probe pins.

Still another aspect of the present invention is an upper die portion ofa die head for aligning probe pins in a first array of first micro-holesformed in a lower die portion of the die head, which includes a spacerportion including first and second surfaces, the first surface adaptedto contact the lower die portion, a first support frame positioned abovethe second surface, an assembly aid film having a second array of secondmicro-holes adapted to receive the probe pins, a second support framepositioned above the first support frame and the assembly aid film, anda sheet joined with the second support frame and having a third array ofthird micro-holes adapted to receive the probe pins.

Yet another aspect of the present invention is a method of replacing aprobe pin in a die head having upper and lower portions, which includesthe following steps: grasping the probe pin; removing the probe pin fromthe die head by pulling the probe pin upwardly and out of the upper andlower portions; and inserting a probe pin in the same location as theprobe pin removed in the removing step by inserting the probe pindownwardly through both upper and lower portions.

Still another aspect of the present invention is a method of assemblingprobe pins in a die head having upper and lower portions, which includesthe following steps: removing at least one of at least one assembly aidfilm and a sheet, each having an array of micro-holes, the at least oneassembly aid film adapted to reside above the upper portion formaintaining the position of the probe pins in the die head by containingeach probe pin in one of the micro-holes; inserting one or more probepins downwardly through both upper and lower portions; and replacing theat least one assembly aid film and sheet removed in the removing step,wherein each of the one or more probe pins inserted in the die head areencircled by one of the array of micro-holes.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of illustrating the invention, the drawings show a formof the invention that is presently preferred. However, it should beunderstood that the present invention is not limited to the precisearrangements and instrumentalities shown in the drawings, wherein:

FIG. 1 is a cross-section of a partially-assembled buckling beam dieknown in the prior art;

FIG. 2 is a cross-section of a fully-assembled buckling beam die knownin the prior art;

FIG. 3 is a cross-section of a partially-assembled buckling beam dieaccording to one embodiment of the present invention;

FIG. 4 is a cross-section of a fully-assembled buckling beam dieaccording to one embodiment of the present invention;

FIG. 5 is a cross-section of a fully-assembled buckling beam accordingto one embodiment of the present invention;

FIG. 6 is a cross-section of a fully-assembled buckling beam dieaccording to one embodiment of the present invention;

FIG. 7 is a top isometric view of an assembled buckling beam dieaccording to one embodiment of the present invention; and

FIG. 8 is an assembly aid for use in assembly the buckling beam dies ofthe present invention.

DETAILED DESCRIPTION

Referring now to FIGS. 3-8 in which like reference numerals indicatelike parts, and in particular to FIGS. 3 and 4, one embodiment of thepresent invention includes an upper die portion 36 of a die head foraligning probe pins 14 in first array of first micro-holes 18 formed inlower die portion 12 of the die head. Upper die portion 36 generallyincludes a spacer portion 38, a support frame 40, and first and secondassembly aid films 42 and 44, respectively.

Spacer portion 38 includes first and second surfaces 46 and 48,respectively. First surface 46 is adapted to contact lower die portion12. Spacer portion 38 is typically an annular configuration having asquare or rectangular cross-section and may be formed from any materialsknown to be suitable as a die portion, e.g., a fiber-filled epoxy, a lowexpansion metal, or a ceramic.

Support frame 40 is typically formed from a metal foil such as a lowexpansion nickel alloy, e.g., sold under the brand name Invar® orsimilar. Support frame 40 is typically similar in shape to spacer 38 butwith a smaller dimension with respect to the longitude of each of probepins 14.

First assembly aid film 42 is typically positioned between secondsurface 48 and support frame 40 and includes a second array of secondmicro-holes 50 adapted to receive probe pins 14. Second assembly aidfilm 44 generally is in contact or close proximity to first assembly aidfilm 42 and has a third array of third micro-holes 52 adapted to receiveprobe pins 14.

Second array of second micro-holes 50 and third array of thirdmicro-holes 52 are patterned to align with one another but at an offsetwith first array of first micro-holes 18 in lower die 12. The amount ofoffset is determined by the offset of each of probe pins 14, i.e., thelateral distance between probe tip 20 and probe head 28. Each of themicro-holes in second array of second micro-holes 50 of first assemblyaid film 42 are generally over-sized, e.g., typically having a diameterapproximately 0.5 mil (0.0005 inch) larger than the diameter of probepins 14, which is smaller than micro-holes 22 in upper die 30 of theprior art. Each of the micro-holes in third array of third micro-holes52 of second assembly aid film 44 are generally smaller than themicro-holes in first assembly aid film 42, e.g., typically having adiameter about 0.1 mil (0.0001 inch) larger than the diameter of each ofprobe pins 14 so that the probe pins can be held in close relativealignment to each other and that each of the third micro-holes iseffectively sealed to prevent debris from entering the die head.

First assembly aid film 42 may also include alignment holes 54, whichare intended to engage a dowel or similar structure (not shown) foraligning the components of upper die portion 36 with lower die 12.Additional structural rigidity may be provided to upper die portion 36by bonding first assembly aid film 42 to support frame 40 and spacerportion 38 using commercially available adhesives, e.g., 3M 2290Structural Adhesive (3M, St. Paul, Minn.) or similar.

First and second assembly aid films 42 and 44 may be any suitablepolymer film, e.g., of the type formed from a polyimide, and are bothtypically at least semi-transparent. First assembly aid film 42generally creates a taut “drum skin” across an aperture 56 that includesa perimeter 58, which is defined within the die head and support frame40, thereby eliminating the non-flatness problem inherent inconventional designs. Second assembly aid film 44 is generally smallerin diameter than first assembly aid film 42 and has an outer perimeter60 that is smaller than perimeter 58 of aperture 56. As a result, secondassembly aid film 44 is typically not connected with support frame 40and instead may float on top first assembly aid film 42.

Referring now to FIG. 5, in an alternative embodiment, an upper dieportion 36′ includes a thin shim 62, which is typically installed aroundouter perimeter 60, and a polymer sheet 64, which is positioned abovesecond assembly aid film 44, typically on top of the shim. Shim 62 istypically installed on top of first assembly aid film 42, which may bemounted to a rigid mounting portion 65 adjacent its perimeter. Mountingportion 65 rests on top of surface 48 of spacer portion 38. Shim 62allows free movement of second assembly film 44 after all the probe pinsare loaded and the second assembly aid film is installed as above.Polymer sheet 64 provides additional rigidity and stability to upper dieportion 36′. Polymer sheet 64 is typically formed from a polyimide ofapproximately 6 mils thickness and has over-sized, typically drilled,micro-holes 66. Polymer sheet 64, spacer portion 38, and shim 62 may bealigned using alignment holes 54 and dowel pins (not shown). Polymersheet 64 is removable for head repair and may be tightly fastened byattaching to shim 62 and spacer 38 using screws or similar. In theembodiment illustrated in FIG. 5, lower die portion 12 and upper dieportion 36′ include four arrays of micro-holes, i.e., first array offirst micro-holes 18, second array of second micro-holes 50, third arrayof third micro-holes 66, and fourth array of fourth micro-holes 52.

Referring now to FIG. 6, in another embodiment, an upper die portion 36″includes spacer portion 38, a first support frame 67, an assembly aidfilm 68, a second support frame 70, and a sheet 72. Spacer portion 38includes first and second surfaces 46 and 48, respectively. Firstsurface 46 is adapted to contact lower die portion 12. First supportframe 67 is positioned adjacent said second surface 48 and typicallyholds assembly aid film 68 taut. Assembly aid film 68 includes a secondarray of second micro-holes 74 adapted to receive probe pins 14.Assembly aid film 68 is generally at least semi-transparent. Secondsupport frame 70 is positioned above said first support frame 67 andsaid assembly aid film 68. Sheet 72 is typically joined with secondsupport frame 70 and includes a third array of third micro-holes 76adapted to receive probe pins 14. Sheet 72 is typically formed from apolyimide of approximately 6 mills thickness. Third array of thirdmicro-holes 76 are typically over-sized, i.e., larger than the diameterof probe pins 14. As in above-described embodiments, second and thirdarrays 72 and 74, respectively, are adapted to be offset from firstarray 18.

Referring now to FIGS. 7 and 8, in another embodiment of the presentinvention, spacer portion 38 may include at least first and secondportions, 38 a and 38 b, respectively, which may be separated from oneanother to facilitate withdrawal and insertion of the spacer portion.Assembly could then take place with first assembly aid film 42 in closeproximity to lower die portion 12. Each of probe tips 20 are passedthrough the assembly aid film micro-holes and lower die portionmicro-holes nearly simultaneously. Referring now to FIG. 8, after all ofprobe pins 14 have been loaded, the die head is placed in a fixture 100that has a plate 102 positioned over the heads of the contacts (notshown) to prevent the contacts from lifting out of lower die portion 12.First assembly aid film 42 may then be raised to its final elevation.The process of raising first assembly aid film 42 generally aligns allthe contacts. Spacer halves 38 a and 38 b may then be inserted betweenfirst assembly aid film 42 and lower die portion 12, and the entire diehead may be pinned and screwed together utilizing alignment holes 54.

Another aspect of the present invention is a method of replacing a probepin in a die head having upper and lower portions. First, sheet 64, 72is removed. In addition, if present, at least one assembly aid filmhaving an array of micro-holes is removed. Next, probe head 28 of theprobe pin 14 to be replaced is grasped using a tweezers or otherappropriately-sized tool. The respective probe pin 14 is then removedfrom the die head by pulling the probe pin upwardly and out of upper andlower portions 36 and 12, respectively. Next, a replacement probe pin 14is inserted inserting in the same location as the probe pin removed byinserting the probe pin downwardly through both upper and lower portions36 and 12, respectively. Then, if present, the at least one assembly aidfilm previously removed is replaced and sheet 64, 72 is replaced.

Still another aspect of the present invention is a method of assemblingprobe pins 14 in a die head. After upper die portion 36 is secured tolower die portion 12 using screws, dowels, or the like, each of probepins 14 are loaded by passing each probe tip 20 and body of the probepin through the over-sized micro-holes in assembly aid films (42 or 68)and then into the corresponding micro-hole 18 in the lower die. Eachassembly aid film is preferably at least semi-transparent so that it ispossible to see each of lower die micro-holes 18 through the assemblyfilm aid, thereby facilitating assembly. In embodiments where more thanone assembly aid sheet is used or a polymer sheet is utilized, both thepolymer sheet and one of the assembly aid sheets may be removed beforeinserting each of probe pins 14 through the remaining assembly aid sheetand into a corresponding micro-hole 18 in lower die portion 12. Then,the removed assembly aid film and polymer sheet are placed on top of theloaded probe-pins causing each probe head 28 to pass through thecorresponding micro-holes on the assembly aid film and polymer sheet.This process continues until all of probe pins 14 are loaded.

The present invention offers a plurality of benefits and advantages overprior art designs. For example, the present invention design enhancesthe repair-ability of the die head. Repairs can be performed by simplyremoving the second assembly aid film and/or polyimide sheet,withdrawing a damaged probe pin through the oversized micro-hole in thefirst assembly aid film, re-inserting a new probe pin, and re-installingthe second assembly aid film. There is no need to remove the upper die,no possibility for the assembly aid film to lift off the probe heads,and no tearing of the film.

The assembly process of the present invention described above offersseveral benefits over prior art assembly processes. First, it generallycan be completed in approximately ⅓ the time required for conventionalassembly. Next, because there is no longer any need to tie down theassembly aid film, there is no possibility for the film to lift off theprobe heads. Also, it greatly reduces the likelihood of bending theprobe pins, since the probe heads no longer have to be bent down andinserted upwards through the assembly aid film.

As described above for one embodiment of the present invention, afterall of the probe pins have been loaded, the second assembly aid filmhaving an array of smaller diameter micro-holes is aligned over theprobe heads and lowered onto the surface of the first assembly aid film.The smaller micro-holes allow the probe pins to be held in closerelative alignment to each other. In addition, since the second assemblyaid film is generally not fixed to the die assembly, it allows freemotion of the probe pins during probe pin compression while stillmaintaining their relative positions. The alignment of the secondassembly aid film to the probe pins is much simpler than the upper diealignment of a conventional design because a) the second assembly aidfilm is preferably at least semi-transparent so the probe pins arealways visible and b) it is not necessary that all the probe pins passthrough all the micro-holes of the array simultaneously, but rather thesecond assembly aid film can be applied to sections of the array instages.

A further advantage of the second assembly array film is evident in thelapping process. As described earlier, the lapping process generatesdebris. Since the second assembly aid film has small diameter, i.e.,“tight,” micro-holes, the lapping debris collects on the top of thisfilm rather than passing into the head assembly. As the debris is on theoutside of the assembly, it may be removed easily without requiringremoval of the upper die. The second assembly aid film may even beremoved entirely and replaced with a clean film.

The present invention also offers improvements over prior art designs inthe area of thermal expansion. For high temperature test applications,the lower and upper dies are made from low coefficient of thermalexpansion (CTE) materials in order to maintain alignment between theprobe pins and the pads that they contact. The pads are typicallylocated on materials having a low CTE. The low CTE materials may presentchallenges in terms of micro-drilling as compared to the conventionalpolyimide materials. In the present invention, the first assemblymounting film is bonded to metal foil having a low CTE, such one soldunder the brand name Invar® or similar. The polyimide film has a higherCTE. However, since the film is very thin, e.g., 1 mil, it cannotsupport compressive forces. It therefore can not force the contactsapart as it expands, which would cause miss-alignment, but rather sagsslightly, greatly alleviating the CTE miss-match problem for upper dies.

The drilling process of the present invention also offers improvementsover prior art processes. The drilling of conventional upper dies istime consuming because the drilling process requires controlled feedrates and multiple passes in order to achieve good quality micro-holesand avoid drill breakage. In contrast, the assembly aid films accordingto the present invention can be punched or laser drilled at low cost andlow lead time. Also, the films of the present invention offeropportunities for slotted holes, which provide advantages in very tightpitch applications, whereas conventional drilling processes aretypically limited to round holes.

Although the invention has been described and illustrated with respectto exemplary embodiments thereof, it should be understood by thoseskilled in the art that the foregoing and various other changes,omissions and additions may be made therein and thereto, without partingfrom the spirit and scope of the present invention.

1. An upper die portion of a die head for aligning probe pins in a firstarray of first micro-holes formed in a lower die portion of the diehead, comprising: a spacer portion including first and second surfaces,said first surface for contacting the lower die portion; a supportframe; and a first assembly aid film attached with said second surfaceand said support frame and having a second array of second micro-holesfor receiving the probe pins, wherein said first assembly aid film isnot part of a laminate; and a second assembly aid film proximal to saidfirst assembly aid film and having a third array of third micro-holesfor receiving the probe pins; a thin shim around an outer perimeter ofsaid third array; and a sheet having over-sized micro-holes, said sheetpositioned on top of said second assembly aid film.
 2. An upper dieportion according to claim 1, wherein said second and third arrays areoffset from the first array.
 3. An upper die portion according to claim1, further comprising: a sheet having over-sized micro-holes, said sheetpositioned on top of said first assembly aid film.
 4. An upper dieportion according to claim 1, wherein said spacer portion includes atleast first and second separateable portions.
 5. An upper die portionaccording to claim 1, wherein both of said first and second assembly aidfilms are at least semi-transparent.
 6. An upper die portion accordingto claim 1, wherein each of the micro-holes of said third array of thirdmicro-holes has a diameter that is selected so that each of themicro-holes of said third array of third micro-holes is substantiallysealed when the probe pins are inserted.
 7. An upper die portionaccording to claim 1, wherein said second assembly aid film is not fixedto said support frame.
 8. An upper die portion according to claim 1,wherein said first assembly aid film is bonded to said support frame. 9.An upper die portion according to claim 1, wherein each of themicro-holes of said third array of third micro-holes has a diameter thatis selected so that debris is substantially prevented from passingthrough said third micro-holes.
 10. An upper die portion according toclaim 1, wherein said first assembly aid film is at least partiallyfabricated from a material having a low coefficient of thermalexpansion.
 11. A die head including alignment mechanisms for aligningprobe pins in the die head, comprising: a lower die portion havingmultiple surfaces, at least one of said multiple surfaces having a firstarray of first micro-holes for receiving the probe pins; an upper dieportion having a spacer portion, a support frame, and a first assemblyaid film, said spacer portion including first and second surfaces, saidfirst surface in contact with at least one of said multiple surfaces ofsaid lower die portion, said first assembly aid film attached with saidsecond surface and said support frame, said first assembly aid filmhaving a second array of second micro-holes for receiving the probepins, wherein said first assembly aid film is not part of a laminate; asecond assembly aid film in contact with said first assembly aid film,said second assembly aid film having a third array of third micro-holesfor receiving the probe pins; a thin shim around an outer perimeter ofsaid third array; and a sheet having over-sized micro-holes, said sheetpositioned on top of said second assembly aid film.
 12. A die headaccording to claim 11, wherein said second and third arrays are offsetfrom the first array.
 13. An upper die portion according to claim 11,further comprising: a sheet having over-sized micro-holes, said sheetpositioned on top of said first assembly aid film.
 14. A die headaccording to claim 11, wherein said spacer portion includes at leastfirst and second separateable portions.
 15. A die head according toclaim 11, wherein both of said first and second assembly aid films areat least semi-transparent.
 16. A die head according to claim 11, whereinsaid second assembly aid film is not fixed to the support frame.
 17. Adie head according to claim 11, wherein said first assembly aid film isbonded to said support frame.
 18. A die head according to claim 11,wherein said first assembly aid film is at least partially fabricatedfrom a material having a low coefficient of thermal expansion.
 19. Anupper die portion of a die head for aligning probe pins in a first arrayof first micro-holes formed in a lower die portion of the die head,comprising: a spacer portion including first and second surfaces, saidfirst surface adapted to contact the lower die portion; a first supportframe positioned above said second surface; an assembly aid film havinga second array of second micro-holes adapted to receive the probe pins,wherein said assembly aid film is not part of a laminate; a secondsupport frame positioned above said first support frame and saidassembly aid film; and a sheet joined with said second support frame andhaving a third array of third micro-holes adapted to receive the probepins; wherein said assembly aid film is prevented from moving in eitheran axial or lateral direction.
 20. An upper die portion according toclaim 19, wherein said second and third arrays are adapted to be offsetfrom the first array.
 21. An upper die portion according to claim 19,wherein said sheet has over-sized micro-holes.
 22. An upper die portionaccording to claim 19, wherein said spacer portion includes at leastfirst and second separateable portions.
 23. An upper die portionaccording to claim 19, further comprising a second assembly aid film incontact with said first assembly aid film, said second assembly aid filmhaving a fourth array of fourth micro-holes adapted to receive the probepins.
 24. An upper die portion according to claim 19, further comprisingmeans for reducing expansion of said assembly aid film.
 25. A method ofreplacing a probe pin in a die head having upper and lower portions,comprising the steps of: providing an upper die portion that includes anassembly aid film that is not part of a laminate; grasping the probepin; removing the probe pin from the die head by pulling the probe pinupwardly and out of the upper and lower portions; and inserting a probepin in the same location as the probe pin removed in said removing stepby inserting the probe pin downwardly through both upper and lowerportions.